lens adaptors

When I bought my first Canon this year, I thought I could get away with an adapter to use my Nikon lenses on the body.
While the adapter works, it forces everything into manual.
Also, you’re forced to look through the lens at the f-stop you’re shooting at, which makes focusing difficult if you want to shoot at say, f:8 or f:11.
I wound up buying a couple of Canon lenses and only use the adapter when I want to use a particular lens for some effect, like one of the really long lenses that I’m not likely to buy again in a Canon mount.
I believe there is an adapter available for Leica R (SLR) lenses, but not the standard M mount, because of the distance to the film plane, I was told.

Take a look at Stephen Gandy’s page:
http://www.cameraquest.com/frames/4saleReos.htm